Mr Prodi is unapologetic about the euro and its perceived weakness on world exchange markets.
He insists that critics are looking at the wrong indicators. "Look, what was expected of the euro?" he says.
"First, lower inflation. OK, we got it. Second, higher growth. Got it. Third, lower unemployment. Got it. Fourth, convergence in budget deficits. Got it. "Nobody ever asked that we have a strong rate of exchange. To do what? I think it will be strong in the future, even too much."
He points out that in the decades before the introduction of the euro the deutschmark fluctuated far more dramatically against the dollar. Yet no one suggests the DM was not a strong currency.
Is the present exchange rate not a problem?
"I say it will go up and down, but the euro was invented to reshape the European economy, and this," he insists, "has been done. Think of the effect of oil prices without the euro."
But had he not also just expressed concern that the exchange rate could go up too high?
"I don't say it will do that now. But really, I don't care, as an economist. We built this currency for ever, not for one year."